网络工程师交换试验手册之九：RIP单播和被动接口实验
实验目的：
根据实验的内容我们可以掌握，被动接口在RIP中的作用，什么是被动接口，以及起了被动接口有什么好处，另外，单播与被动接口有什么关系，二者如何配合使用。
实验拓扑：
实验内容：
1． 路由器的基本RIP配置
r1#sh run
Building configuration...
Current configuration : 457 bytes
!
version 12.2
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname r1
!
!
ip subnet-zero
!
!
!
!
interface Ethernet0
ip address 199.99.1.1 255.255.255.0
!
interface Serial0
no ip address
shutdown
!
interface Serial1
ip address 199.99.2.1 255.255.255.0
clockrate 64000
!
router rip
network 199.99.1.0
network 199.99.2.0
!
no ip http server
ip classless
!
!
line con 0
line aux 0
line vty 0 4
!
end
r2#sh run
Building configuration...
00:51:56: %SYS-5-CONFIG_I: Configured from console by console
Current configuration : 599 bytes
!
version 12.2
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname r2
!
!
ip subnet-zero
!
!
!
!
interface Loopback0
ip address 198.98.98.1 255.255.255.0
!
interface Loopback1
ip address 198.98.97.1 255.255.255.0
!
interface Ethernet0
ip address 199.99.3.1 255.255.255.0
!
interface Serial0
ip address 199.99.2.2 255.255.255.0
!
interface Serial1
no ip address
shutdown
!
router rip
network 198.98.97.0
network 198.98.98.0
network 199.99.2.0
network 199.99.3.0
!
ip http server
ip classless
!
!
line con 0
line aux 0
line vty 0 4
!
end
2．查看两台路由器的路由表，看路由表象是否已经全。
r1#sh ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
R 199.99.3.0/24 [120/1] via 199.99.2.2, 00:00:25, Serial1
C 199.99.2.0/24 is directly connected, Serial1
C 199.99.1.0/24 is directly connected, Ethernet0
R 198.98.97.0/24 [120/1] via 199.99.2.2, 00:00:25, Serial1
R 198.98.98.0/24 [120/1] via 199.99.2.2, 00:00:25, Serial1
r2#sh ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
C 199.99.3.0/24 is directly connected, Ethernet0
C 199.99.2.0/24 is directly connected, Serial0
R 199.99.1.0/24 [120/1] via 199.99.2.1, 00:00:11, Serial0
C 198.98.97.0/24 is directly connected, Loopback1
C 198.98.98.0/24 is directly connected, Loopback0
3．查看两台路由器的数据库，其实数据库才应该是我们真正关心的东西，能够进入数据库就一定可以进入路由表。
r1#sh ip rip da
198.98.97.0/24 auto-summary
198.98.97.0/24
[1] via 199.99.2.2, 00:00:18, Serial1
198.98.98.0/24 auto-summary
198.98.98.0/24
[1] via 199.99.2.2, 00:00:18, Serial1
199.99.1.0/24 auto-summary
199.99.1.0/24 directly connected, Ethernet0
199.99.2.0/24 auto-summary
199.99.2.0/24 directly connected, Serial1
199.99.3.0/24 auto-summary
199.99.3.0/24
[1] via 199.99.2.2, 00:00:18, Serial1
r2#sh ip rip da
198.98.97.0/24 auto-summary
198.98.97.0/24 directly connected, Loopback1
198.98.98.0/24 auto-summary
198.98.98.0/24 directly connected, Loopback0
199.99.1.0/24 auto-summary
199.99.1.0/24
[1] via 199.99.2.1, 00:00:07, Serial0
199.99.2.0/24 auto-summary
199.99.2.0/24 directly connected, Serial0
199.99.3.0/24 auto-summary
199.99.3.0/24 directly connected, Ethernet0
4．查看R1中的debug信息，看RIP发包的情况。
r1#
00:57:40: RIP: ignored v1 update from bad source 199.99.3.1 on Ethernet0
00:57:40: RIP: received v1 update from 199.99.2.2 on Serial1
00:57:40: 198.98.97.0 in 1 hops
00:57:40: 198.98.98.0 in 1 hops
00:57:40: 199.99.3.0 in 1 hops
r1#
00:57:49: RIP: sending v1 update to 255.255.255.255 via Ethernet0 (199.99.1.1)
00:57:49: RIP: build update entries
00:57:49: network 198.98.97.0 metric 2
00:57:49: network 198.98.98.0 metric 2
00:57:49: network 199.99.2.0 metric 1
00:57:49: network 199.99.3.0 metric 2
00:57:49: RIP: sending v1 update to 255.255.255.255 via Serial1 (199.99.2.1)
00:57:49: RIP: build update entries
00:57:49: network 199.99.1.0 metric 1
我们发现R1把收到的所有的包，以广播的形式向自己直连的接口进行扩散，达到路由学习的目的，如果我们不允许R1的这种扩散，我们需要通过被动接口来实现。
5．被动接口与debug信息
r1(config)#router rip
r1(config-router)#passive-interface default 配置所有的接口为被动，所谓被动就是只收不发。
这时候看debug得出：
00:57:40: RIP: ignored v1 update from bad source 199.99.3.1 on Ethernet0
00:57:40: RIP: received v1 update from 199.99.2.2 on Serial1
00:57:40: 198.98.97.0 in 1 hops
00:57:40: 198.98.98.0 in 1 hops
00:57:40: 199.99.3.0 in 1 hops
它只是收到数据包，而不发包，这个时候，我们重新计算R1与R2的路由表
r1#clear ip route *
r2#clear ip route *
查看r2的路由表发现没有任何路由信息了
r2#sh ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
C 199.99.3.0/24 is directly connected, Ethernet0
C 199.99.2.0/24 is directly connected, Serial0
R 199.99.1.0/24 is possibly down, routing via 199.99.2.1, Serial0
我们惊喜的发现路由现在的状态是possibly down了，观察这个现象。
C 198.98.97.0/24 is directly connected, Loopback1
C 198.98.98.0/24 is directly connected, Loopback0
这时候我们发现ping也不通了，这时候我们只想保证R1与R2的直连接口之间发送数据包，而R1不想向其他接口扩散。
r1(config-router)#neighbor 199.99.2.2
r1(config-router)#õ
r2(config)#router rip
r2(config-router)#nei
r2(config-router)#neighbor 199.99.2.1
r1#clear ip route *
r2#clear ip route *
再次看R1的debug
r1#debug ip rip
RIP protocol debugging is on
r1#
r1#
r1#
01:10:03: RIP: ignored v1 update from bad source 199.99.3.1 on Ethernet0
01:10:03: RIP: received v1 update from 199.99.2.2 on Serial1
01:10:03: 198.98.97.0 in 1 hops
01:10:03: 198.98.98.0 in 1 hops
01:10:03: 199.99.3.0 in 1 hops
01:10:03: RIP: received v1 update from 199.99.2.2 on Serial1
01:10:03: 198.98.97.0 in 1 hops
01:10:03: 198.98.98.0 in 1 hops
01:10:03: 199.99.3.0 in 1 hops
01:10:12: RIP: sending v1 update to 199.99.2.2 via Serial1 (199.99.2.1)
01:10:12: RIP: build update entries
01:10:12: network 199.99.1.0 metric 1
我们已经发现两端可以互相发和接受了，但是R1不向其他的接口扩散。
实验总结：
通过这个扩展实验的训练，我们更加清楚的认识到RIP的特性，这个实验是比较重要的，希望大家可以完成。
根据实验的内容我们可以掌握，被动接口在RIP中的作用，什么是被动接口，以及起了被动接口有什么好处，另外，单播与被动接口有什么关系，二者如何配合使用。
实验拓扑：
实验内容：
1． 路由器的基本RIP配置
r1#sh run
Building configuration...
Current configuration : 457 bytes
!
version 12.2
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname r1
!
!
ip subnet-zero
!
!
!
!
interface Ethernet0
ip address 199.99.1.1 255.255.255.0
!
interface Serial0
no ip address
shutdown
!
interface Serial1
ip address 199.99.2.1 255.255.255.0
clockrate 64000
!
router rip
network 199.99.1.0
network 199.99.2.0
!
no ip http server
ip classless
!
!
line con 0
line aux 0
line vty 0 4
!
end
r2#sh run
Building configuration...
00:51:56: %SYS-5-CONFIG_I: Configured from console by console
Current configuration : 599 bytes
!
version 12.2
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname r2
!
!
ip subnet-zero
!
!
!
!
interface Loopback0
ip address 198.98.98.1 255.255.255.0
!
interface Loopback1
ip address 198.98.97.1 255.255.255.0
!
interface Ethernet0
ip address 199.99.3.1 255.255.255.0
!
interface Serial0
ip address 199.99.2.2 255.255.255.0
!
interface Serial1
no ip address
shutdown
!
router rip
network 198.98.97.0
network 198.98.98.0
network 199.99.2.0
network 199.99.3.0
!
ip http server
ip classless
!
!
line con 0
line aux 0
line vty 0 4
!
end
2．查看两台路由器的路由表，看路由表象是否已经全。
r1#sh ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
R 199.99.3.0/24 [120/1] via 199.99.2.2, 00:00:25, Serial1
C 199.99.2.0/24 is directly connected, Serial1
C 199.99.1.0/24 is directly connected, Ethernet0
R 198.98.97.0/24 [120/1] via 199.99.2.2, 00:00:25, Serial1
R 198.98.98.0/24 [120/1] via 199.99.2.2, 00:00:25, Serial1
r2#sh ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
C 199.99.3.0/24 is directly connected, Ethernet0
C 199.99.2.0/24 is directly connected, Serial0
R 199.99.1.0/24 [120/1] via 199.99.2.1, 00:00:11, Serial0
C 198.98.97.0/24 is directly connected, Loopback1
C 198.98.98.0/24 is directly connected, Loopback0
3．查看两台路由器的数据库，其实数据库才应该是我们真正关心的东西，能够进入数据库就一定可以进入路由表。
r1#sh ip rip da
198.98.97.0/24 auto-summary
198.98.97.0/24
[1] via 199.99.2.2, 00:00:18, Serial1
198.98.98.0/24 auto-summary
198.98.98.0/24
[1] via 199.99.2.2, 00:00:18, Serial1
199.99.1.0/24 auto-summary
199.99.1.0/24 directly connected, Ethernet0
199.99.2.0/24 auto-summary
199.99.2.0/24 directly connected, Serial1
199.99.3.0/24 auto-summary
199.99.3.0/24
[1] via 199.99.2.2, 00:00:18, Serial1
r2#sh ip rip da
198.98.97.0/24 auto-summary
198.98.97.0/24 directly connected, Loopback1
198.98.98.0/24 auto-summary
198.98.98.0/24 directly connected, Loopback0
199.99.1.0/24 auto-summary
199.99.1.0/24
[1] via 199.99.2.1, 00:00:07, Serial0
199.99.2.0/24 auto-summary
199.99.2.0/24 directly connected, Serial0
199.99.3.0/24 auto-summary
199.99.3.0/24 directly connected, Ethernet0
4．查看R1中的debug信息，看RIP发包的情况。
r1#
00:57:40: RIP: ignored v1 update from bad source 199.99.3.1 on Ethernet0
00:57:40: RIP: received v1 update from 199.99.2.2 on Serial1
00:57:40: 198.98.97.0 in 1 hops
00:57:40: 198.98.98.0 in 1 hops
00:57:40: 199.99.3.0 in 1 hops
r1#
00:57:49: RIP: sending v1 update to 255.255.255.255 via Ethernet0 (199.99.1.1)
00:57:49: RIP: build update entries
00:57:49: network 198.98.97.0 metric 2
00:57:49: network 198.98.98.0 metric 2
00:57:49: network 199.99.2.0 metric 1
00:57:49: network 199.99.3.0 metric 2
00:57:49: RIP: sending v1 update to 255.255.255.255 via Serial1 (199.99.2.1)
00:57:49: RIP: build update entries
00:57:49: network 199.99.1.0 metric 1
我们发现R1把收到的所有的包，以广播的形式向自己直连的接口进行扩散，达到路由学习的目的，如果我们不允许R1的这种扩散，我们需要通过被动接口来实现。
5．被动接口与debug信息
r1(config)#router rip
r1(config-router)#passive-interface default 配置所有的接口为被动，所谓被动就是只收不发。
这时候看debug得出：
00:57:40: RIP: ignored v1 update from bad source 199.99.3.1 on Ethernet0
00:57:40: RIP: received v1 update from 199.99.2.2 on Serial1
00:57:40: 198.98.97.0 in 1 hops
00:57:40: 198.98.98.0 in 1 hops
00:57:40: 199.99.3.0 in 1 hops
它只是收到数据包，而不发包，这个时候，我们重新计算R1与R2的路由表
r1#clear ip route *
r2#clear ip route *
查看r2的路由表发现没有任何路由信息了
r2#sh ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
C 199.99.3.0/24 is directly connected, Ethernet0
C 199.99.2.0/24 is directly connected, Serial0
R 199.99.1.0/24 is possibly down, routing via 199.99.2.1, Serial0
我们惊喜的发现路由现在的状态是possibly down了，观察这个现象。
C 198.98.97.0/24 is directly connected, Loopback1
C 198.98.98.0/24 is directly connected, Loopback0
这时候我们发现ping也不通了，这时候我们只想保证R1与R2的直连接口之间发送数据包，而R1不想向其他接口扩散。
r1(config-router)#neighbor 199.99.2.2
r1(config-router)#õ
r2(config)#router rip
r2(config-router)#nei
r2(config-router)#neighbor 199.99.2.1
r1#clear ip route *
r2#clear ip route *
再次看R1的debug
r1#debug ip rip
RIP protocol debugging is on
r1#
r1#
r1#
01:10:03: RIP: ignored v1 update from bad source 199.99.3.1 on Ethernet0
01:10:03: RIP: received v1 update from 199.99.2.2 on Serial1
01:10:03: 198.98.97.0 in 1 hops
01:10:03: 198.98.98.0 in 1 hops
01:10:03: 199.99.3.0 in 1 hops
01:10:03: RIP: received v1 update from 199.99.2.2 on Serial1
01:10:03: 198.98.97.0 in 1 hops
01:10:03: 198.98.98.0 in 1 hops
01:10:03: 199.99.3.0 in 1 hops
01:10:12: RIP: sending v1 update to 199.99.2.2 via Serial1 (199.99.2.1)
01:10:12: RIP: build update entries
01:10:12: network 199.99.1.0 metric 1
我们已经发现两端可以互相发和接受了，但是R1不向其他的接口扩散。
实验总结：
通过这个扩展实验的训练，我们更加清楚的认识到RIP的特性，这个实验是比较重要的，希望大家可以完成。